METALS RECOVERY FROM THE GOLD PRESSURE OXIDATION STAGE EFFLUENT USING SOLVENT EXTRACTION

Abstract

– The gold mining, accompanied with the production increase, generates a large effluent amount throughout its process, resulting in several environmental impacts if not correctly destined. In this context, the solvent extraction emerges as an alternative to recover value-added compounds present in this effluent. In this work, Cyanex 272 was employed, in different aqueous/organic (A/O) ratios, to recover metals from a pressure oxidation stage synthetic effluent. The metals concentration in the aqueous phase was determined by atomic absorption spectroscopy. Distribution coefficient and separation factors were calculated. The highest concentration in the organic phase was iron due to the higher driving force for the extraction. The highest average removal was for manganese (40.8 %). Furthermore, the highest selectivity was obtained for the 2/1 A/O ratio, being the manganese the metal that presented greater selectivity against iron.